Dancer roll apparatus



Nov. 12, 1968 M. ZOBENICA DANCER ROLL APPARATUS 3 Sheets-Sheet 1 Filed Aug.

INVENTOR MILAN ZOBENICA FIGI MC uzuuv, FARRINGTON, PEARNE a sonoou ATTORNEYS 3 Sheets-Sheet 2 INVENTOR MILAN ZOBENICA ATTORNEYS Nov. 12, 1968 M. ZOBENICA DANCER ROLL APPARATUS Filed Aug.

MC NENNY, FARRINGTON- PEARNE 8 GORDON Nov. 12, 1968 M. ZOBENICA 3,410,468

DANCER ROLL APPARATUS Filed Aug. 5, 1966 3 Sheets-Sheet 5 INVENTOR MILAN ZOBENIGA MC NENNY, FARRINGTON, PEARNE 8 GORDON ATTORNEYS United States Patent 3,410,468 DANCER ROLL APPARATUS Milan Zobenica, Parma, Ohio, assignor to Indu.trial Ovens, Incorporated, Cleveland, Ohio, a corporation of Ohio Filed Aug. 3, 1966, Ser. No. 569,943 Claims. (Cl. 226--44) ABSTRACT OF THE DISCLOSURE A dancer roll assembly for varpingthe loop length of tensioned strip material which includes at least one loop maintaining roll. The roll is provided with a sprocket at each end and each sprocket is received in its own downwardly extending chain loop. The chain loop comprises a free-hanging take-up reach for varying the elevation of the dancer roll and a holding reach which extends along a back-up member. The tensioned strip material is guided to and from the dancer roll so that the tension of the strip material biases the dancer roll and its sprockets against the holding reaches and their back-up members so that the sprockets and their holding reaches interact as rack and pinion linkages.

This invention relates to a dancer roll assembly for varying the loop length of tensioned strip material. A specific application for the invention is in the hot-stretching of tire cord fabric at controlled temperatures under web loads of as much as several thousand pounds. pparatus of this kind is described and schematically illustrated in the US. Patent 2,994,133, particular reference being made to FIGURE 4 thereof.

Under high web tension loads, maintaining the level of the dancer roll while meeting all the other requirements of economic installation and operation has been a problem. Relatively light chains or hangers for the dancer roll are too easily over-stressed, particularly when, as frequently happens, the training of the Web causes it to shift slightly along the length of the roll, thereby substantially increasing the load at one end of the roll. If the relatively light chains or hangers are doubled, the resulting suspension does not have the necessary stability since the roll ends are free to sway transversely. .On the other hand, heavy chains or hangers are bulky and require ponderous take-up apparatus, making them costly to install and unwieldy in operation.

The present invention provides apparatus in which relatively light hangers may be used but in which the dancer roll or rolls are supported in a stable manner and r in which roll level may be closely maintained under high web tension loads even when the training of the web causes it to shift along the length of the roll to thereby change the relative loading of the hangers at the respective ends of the roll. The objects and advantages of the invention will be better understood from the following description of one embodiment of the invention, which is given by way of example.

In the accompanying drawings, FIGURE 1 is a fragmentary side elevational view of apparatus illustrating the invention. FIGURE 2 is a fragmentary view of one end of the dancer roll support structure taken on an enlarged scale from the plane of line 22 in FIGURE 1. FIGURE 3 is an end view of the apparatus seen in FIG- URE 2 together with the dancer roll itself.

In FIGURE 1 strip material in the form of a tire fabric web 11 is threaded through guide rolls 12-15 and dancer rolls 16 and 17. The dancer roll 16 carries a loop 21 of the strip material 11. The dancer roll 17 carries a loop 22 of the strip material 11.

The dancer roll 16 is provided at one end with a Patented Nov. 12, 1968 sprocket 25, and at the opposite end with, a similar sprocket (not shown). The sprocket 25 is received in a chain loop which supports the roll 16 against the tension of the strip material 11. The chain loop comprises a holding reach 27 that extends along a back-up member 28 along which it is free to slide. The back-up member 28 may comprise simply the fiat face of a structural supporting beam or the like. The chain loop also comprises a freehanging take-up reach 29. The sprocket at the opposite end of the dancer roll 16 is supported by a similar chain loop whose holding reach is supported by and can slide along a back-up member (all not shown).

The guide rolls 12 and 13 guide the tensioned strip material 11 to and from the roll 16 along the directions of the up-feeding and down-feeding reaches of the loop 21. These directions are such as to bias the roll 16 and its end sprockets against the holding reaches of the chain loop and the back-up member for such holding reaches. If such biasing is not sufficiently positive, the roll 12 and/or the roll 13 may be positioned slightly to the left of the positioning shown in FIGURE 1 to thereby increase such biasing. In the particular example illustrated, and desirably, the holding reaches (e.g. 27) and their back-up member (eg 28) are vertical, and the free-hanging takeup reaches (e.g. 29) are slightly off vertical, as shown.

A sprocket 31 is adapted to take up or let out the reach 29 and a similar sprocket behind the sprocket 31 (not shown) is adapted to take up or let out the other free-hanging reach behind the reach 29. These latter sprockets'may be keyed to the same shaft and may be intermittently and reversibly driven by a suitable power linkage (not shown). The latter two sprockets together with the power linkage constitutes means for taking up or letting out the take-up reaches of the chain loop supporting the roll 16.

During such taking up, or letting out, the sprocket 25 and its corresponding member at the other end of the roll 16 are at all times biased into engagement with the holding reaches (cg. 27) which function as vertical racks.

Thus it will be understood that the sprockets of the dancer roll 16 and their associated holding reaches on the chain loops interact as rack and pinion linkages.

The dancer roll 16 and its associated apparatus may be counter-balanced by a dancer roll 17 and its associated apparatus in such a way that increasing the length of the loop 21 decreases the length of the loop 22 and vice versa. Thus there is a sprocket corresponding to the sprocket 25, a sprocket 41 corresponding to the sprocket 31 and a chain loop consisting of a holding reach 37, a freehanging take-up reach 39, and a back-up member 38. Corresponding elements are associated with the other end ofthe dancer roll 17.

Respective ends of the two dancer rolls 16 and 17 may be interconnected by flexible linkage means such as the holddown chain 51 which is Opposed to the chain loop at each of the dancer rolls and thereby provides a safety hold-down means for each dancer roll to prevent dangerous catapulting of the dancer roll in the event of web breakage under high tension. These flexible hold-down means are guided around suitable means such as the sprockets 52.

Suitable bearings, such as bearing 54 (FIGURE 2) may be provided for the dancer rolls and the sprockets 35. The various elements of each dancer roll assembly may be carried on a cross-support 56, on which may also be mounted equipment such as oil cups 57.

Fluid may be circulated through one or both dancer rolls. Thus if loop 21 is adapted to extend into a heating chamber 64 (FIGURE 1) and loop 22 consititues a cooling station, coolant such as water may be circulated through the roll 17 in order to promote cooling of the strip material at the cooling station. The water may be introduced at one end of the roll and emptied from the other via flexible lines such as the line 58 which may be supported by the double-eye lufling 59 and may feed via the joint 60 designed to accommodate rotary motion.

There may be provided in association with the dancer roll 16 means for adjusting each one of the holding reaches 27 independently of the other. This means may consist of hydraulic cylinders 43. These cylinders may be controlled by solenoid valve means (not shown) for corrective taking up and letting out of the holding reaches, the direction (and preferably magnitude) of the error in roll level being sensed by suitable level sensing means 62 such as a pendulum, mercury switch, or electrolytic potentiometer. This maintains the roll in a level state independently of all transient conditions such as slight shifting of the web material on the roll, and even independently of varying stress and strains on the associated loops 21 and 22. The same means may be provided in association with the dancer roll 17 as shown. Such level control dispenses with any need for relatively expensive self-aligning bearings at the ends of the dancer rolls 16 and 17.

The invention is not restricted to the slavish imitation of each and every one of the details described above, which have been set forth merely by way of example with the intent of most clearly disclosing the teachings of the invention. Obviously, devices may be provided which change, eliminate, or add certain specific details without departing from the invention.

What is claimed is:

1. A dancer roll assembly for varying the loop length of tensioned strip material comprising a dancer roll, sprocket means at each end of the dancer roll, each sprocket means being received in its own downwardly extending chain loop, with said chain loops supporting said roll against strip tension and each said loop comprising a holding reach extending along a back-up member and also comprising a free-hanging take-up reach, means for guiding tensioned strip material to and from said roll with the tension of said strip material applied along directions to bias said roll and sprockets against said holding reaches and their back-up members, and means for taking up or letting out said take-up reaches to vary the length of the loop of strip material supported by the roll whereby said sprockets and said holding reaches interact as rack and pinion linkages.

2. Apparatus as defined in claim 1, and means for adjusting the longitudinal position of each holding reach independently of the other.

3. A counterbalanced array including two assemblies of dancer roll apparatus as recited in claim 1 with the take-up reaches of the two assemblies being interconnected whereby taking up in one assembly is accompanied by letting out in the other and the two assemblies are counterbalanced.

4. Apparatus as defined in claim 3 in which the two dancer rolls are interconnected by flexible linkage means that is opposed to the chain loop at each dancer roll to thereby provide safety hold-down means for each dancer roll.

5. A dancer roll assembly for varying loop lengths of tensioned strip material comprising two dancer rolls, sprocket means at each end of each dancer roll, each sprocket means being received in its own downwardly extending chain loop, with said chain loops supporting said roll against strip tension and each said loop comprising a holding reach extending along a backup member and also comprising a free-hanging take-up reach, means for guiding tensioned strip material to and from each said roll with the tension of the strip material applied along directions to bias said rolls and sprockets against said holding reaches and their back-up members, means for taking up or letting out said take-up reaches to vary the lengths of the loops of strip material supported by the rolls, whereby said sprockets and said holding reaches interact as rack and pinion linkages, said take-up reaches of each of said rolls being interconnected so that the rolls move in opposite directions whereby taking up in one roll is accompanied by letting out in the other, said rolls being counterbalanced, and said two dancer rolls being interconnected by flexible linkage means that is opposed to the chain loop at each dancer roll to thereby provide safety hold-down means for each dancer roll.

References Cited UNITED STATES PATENTS 3,045,360 7/1962 Alexeff et a1. 22644 X 3,084,841 4/1963 Hata et al. 226113 3,282,488 11/1966 Bauer et a1.

EVON C. BLUNK, Primary Examiner. M. L. AJEMAN, Assistant Examiner. 

